Effectiveness of various botanical traps against apple snail, Pomacea maculata (Gastropoda: Ampullariidae) in a rice field

The adverse effects of molluscicides applied for the control of the invasive apple snails, Pomacea spp., have led to the search for eco-based cultural, mechanical and biological control techniques. Therefore, a field study on the relative effectiveness of locally available and cost effective plant-based traps against Pomacea spp. was conducted. Results showed jackfruit skin (9.03 ± 0.60/m2 and 6.03 ± 0.60/m2) and damaged pomelo (9.00 ± 0.61/m2 and 5.78 ± 0.74/m2) were relatively more effective than tapioca leaves, water spinach leaves and old newspaper. Snails also displayed preference for fresh materials as compared to rotten materials. Thus, incorporating these findings in rice fields during early susceptible growth will ease the collection and destruction of snails

Population fluctuation and dispersion patterns of apple snails, Pomacea spp. (Gastropoda: Ampullariidae) in a rice ecosystem

A field study was conducted for two consecutive rice-growing seasons from August, 2013 to May, 2014 to understand the population dynamics of exotic apple snails, Pomacea spp. (Ampullariidae), as affected by ambient weather and aquatic weeds. A one-acre rice field was divided into four blocks and eight samples per block were taken using a 0.5x0.5m quadrat. Collected snails were recorded as numbers of egg clutches, juveniles, adult females and males. Average rainfall, relative humidity, temperature and water pH, along with number of aquatic weeds and seedlings, were also recorded. Results confirmed the presence of only Pomacea maculata. The numbers of egg clutches, juveniles and adults were relatively high during the off-season as compared to the main-season. Meanwhile, relative humidity had a significant effect on the number of egg clutches, and rainfall affected the densities of juveniles and adults. Among the weeds, Limnocharis flava (Alismataceae) had significant effect on the densities of different snail stages. Different stages showed uniform dispersion pattern during both seasons due presumably to continuous availability of water and abundant food. Thus, results obtained could be helpful in understanding the population dynamics of P. maculata and devising appropriate management strategy

Foes can be Friends: Laboratory Trials on Invasive Apple Snails, Pomacea spp. Preference to Invasive Weed, Limnocharis flava (L.) Buchenau Compared to Rice, Oryza sativa L

A B S T R A C T Rice ecosystem often involves a complex interaction of various pest species with rice. An example of such interaction is that between the invasive Pomacea spp. and Limnocharis flava. Both invasive pests have caused heavy loss to rice in Southeast Asia including Malaysia. However, information on the interaction of both invasive pests in the rice field is still lacking. Therefore, a laboratory study was conducted to determine the feeding preference and growth pattern of P. canaliculata and P. maculata for rice and L. flava based on choice and no-choice experiments. It was found that the three different sizes (1, 2 and 3 cm) of both Pomacea spp. used in this study showed significantly less preference for rice stems and leaves as compared to L. flava leaves and stems. Among all the studied plant materials, rice stems were the least consumed. Moreover, higher shell length growth and weight gain was also recorded in the two species when fed with L. flava. This further suggests that the two Pomacea spp. have the potential to be used as an effective bio-control agent against the invasive weed in the rice ecosystem during the early stages of rice growth, in combination with a proper management of irrigation water. In addition, L. flava can also be used as a trap crop in rice fields to ease the collection and destruction of apple snails

Repellent potential of medicinal oils against Tribolium castaneum (Herbst) under laboratory conditions

Laboratory experiments were conducted to determine repellency of five local medicinal oils i.e., neem Azadirachta indica A. Juss., castor Ricinus communis L., rapeseed Brassica napus L., lettuce Lactuca sativa L. and chamomile Anthemis cotula L. against Tribolium castaneum Herbst, each applied at 0.1, 0.5- and 1.0-ml doses. A glass cylinder divided into A, B and C sections with one end close was used. Fifty grams of wheat flour was placed at A and C ends. Twenty freshly emerged T. castaneum was released at the center of cylinder (B). The data was recorded after one-, two- and three-days to count number of T. castaneum at A and C for calculating percentage repellency. All the oils showed repellent potential against T. castaneum as their repellency increased with dose and time exposure. After three days, 100% repellency of T. castaneum was recorded in 0.5- and 1.0-ml doses of neem oil, followed by 6.67±3.33% repellency at 0.1 ml neem oil. After three days, the maximum repellency of T. castaneum in rapeseed, castor, chamomile, and lettuce was 86.67±7.26, 76.67±6.01, 76.67±4.41, and 75.00±7.64%, respectively, all recorded at 1.0 ml dose. Overall, neem oil exhibited significantly more repellency of T. castaneum, whereas castor, lettuce, rapeseed and chamomile were found non-significant with each other. Among doses, although highest repellency was recorded at 1.0 ml dose, but not significantly different from 0.5 ml dose of the individual oil. Therefore, 0.5 ml should be applied per 50 grams of wheat flour to get effective repellency of T. castaneum

Efficiency of Acerophagus papayae on different host stage combinations of papaya mealybug, Paracoccus marginatus

Acerophagus papayae is a koinobiont endoparasitoid of the invasive papaya mealybug, Paracoccus marginatus and has been introduced as a classical bio-control agent of the mealybug in many countries. Considering the importance, parasitism efficiency of A. papayae against various life stages of P. marginatus was conducted in choice experiments. Results suggested that A. papayae showed higher parasitism efficiency towards third instar female nymphs and adult female P. marginatus in comparison to second instar male. However, second instar male nymphs were more preferred in comparison to second instar female nymphs. Acerophagus papayae exhibited a highly significant sex-biased development ratio as a female dominant progeny emerged while feeding on female hosts and vice versa. No difference was recorded in the developmental time of male and female A. papayae, however, females matured one day later than males. The only gregarious behaviour of A. papayae was recorded on adult female P. marginatus as more than one adult parassitoid emerged from a single host. Study results suggested that A. papayae has a tremendous potential to be utilized in classical biological control programs against P. marginatus as it showed more preference towards female hosts; hence not only reducing available pest population but also will affect the pest population of next generation

Ecobiological aspects of invasive apple snails (Pomacea spp.) in rice fields, Peninsular Malaysia

Alien invasive apple snails, Pomacea canaliculata Lamarck and Pomacea maculata Perry were introduced into Malaysia around 1991. Since their introduction, Pomacea spp. have damaged vast area under rice cultivation and are major threat to rice self sufficiency in Malaysia. However, no thorough research has been done on their ecobiological aspects in the country, especially in Peninsular Malaysia. Therefore, this study focused on understanding the different ecobiological aspects of these apple snails. Studies on the abundance of Pomacea spp. in twenty five rice fields of five states in Peninsular Malaysia, confirmed the presence of P. maculata and P. canaliculata. Pomacea maculata was more abundant and widely distributed. Population of P. canaliculata was not recorded in Penang. Rice fields in Perak showed the highest population of snails (10.13 snails / m2). The lowest population was recorded from rice fields of Kelantan and Kedah during sowing and harvesting, respectively. Population of snails was significantly higher during sowing of rice as compared to harvesting due to the presence of plenty of water and young rice seedlings as their food. Population fluctuation of egg, juvenile and adult snails in a rice field over two rice growing seasons from August, 2013 to May, 2014 highlighted comparatively higher populations during off season in comparison to main season. Population of different stages of P. maculata increased during reproductive and ripening stages of rice. No population of juveniles, females and males was recorded at harvesting due to water drain out from rice field. Higher populations were significantly correlated to relative humidity, rainfall, and density of Limnocharis flava and Ischaemum rugosum. Different indices of population dispersion i.e., variance to mean ratio, Lloyd index and Green Co-efficient mostly confirmed regular or uniform dispersion pattern of various stages of P. maculata. However, Iwao’s patchiness regression and Taylor’s power law mostly confirmed aggregated dispersion pattern. Findings of the growth studies confirmed that size of one day hatchlings of P. canaliculata was significantly higher than P. maculata. Comparatively higher growth rate was observed in P. canaliculata than P. maculata with both species sexually matured during 27th and 32nd weeks, respectively. No significant difference was observed in shell length, height and width of the two species at maturity. Both Pomacea spp. started consuming rice during 4th week after hatching from eggs. Mating and oviposition behavior studies confirmed higher mating frequency, oviposition duration and higher number of eggs per clutch of smaller size along with more eggs per minute in P. maculata. Mating and oviposition in both species occurred mostly during the night hours. No difference was recorded for mating duration, oviposition frequency, hatching success and hatching period between two species. Highly significant correlation between oviposition duration and total number of eggs was only observed in P. canaliculata. Feeding preference of 1, 2 and 3 cm sized snails of the two species on leaves and stems of rice and L. flava confirmed higher preference for L. flava in all three sizes based on higher consumption. Limnocharis flava also supported higher growth and weight gain in both Pomacea spp. Rice stems supported the least growth and weight gain. Study on damage potential of two Pomacea spp. to rice established by direct seeding and 14, 21 and 28 days old transplanted seedlings showed that both species caused 100% loss to direct seeded and 14 days transplanted rice. Damage decreased with older transplanted seedlings with the least damage recorded in 28 days old transplanted rice. No loss of seedlings by two Pomacea spp. was recorded in 21 and 28 days old transplanted rice after 5th and 4th weeks, respectively. Sowing methods and damage by Pomacea spp. caused considerable reduction in number of tillers, panicles and Leaf Area Index. Higher number of these parameters was recorded in 21 days old transplanted rice control treatment. Additional space in 28 days old transplanted rice snail infested plots due to missing seedlings compensated them by producing more spikelets per panicle, grain filling percentage and grain harvest index. Accordingly, yields in 28 days old transplanted rice treatments damaged by Pomacea spp. were comparable with control treatments of 28 and 21 days old transplanted rice. Studies on the effect of water levels of 5 and 2 cm, and densities of 1, 2 and 3 snails per plot of Pomacea spp. confirmed significantly higher damage by all the snail densities at 5 cm water level. Higher damage was recorded at a density of 3 snails / plot of either species. No significant difference between P. maculata and P. canaliculata was recorded in rice grown by different methods at two water levels, suggesting the same damage potential of the two species to rice

Impact of Different Oils as Biopesticide against Sucking Insect Pests in Cotton

The study was conducted to evaluate the effect of various botanical products on population of sucking complex on cotton crop. The study was conducted at the experimental area of Entomology section, Agriculture Research Institute, Tando Jam during the Kharif Season-2004. Five bio-pesticides i.e. neem oil (500ml/acre), cooking oil (750 ml/acre), linseed oil (750ml/acre), hing (290gm/acre) and cotton oil (750ml/acre) were applied twice against sucking complex (jassid, thrip and whitefly) and compared with an untreated control. It was observed that the efficacy of different bio-pesticides against sucking complex (jassid, whitefly and thrips) varied significantly. All products reduced pest population during both sprays. On an average, neem oil (63.27%) and cotton oil (62.01%) were found to be superior in reducing sucking pest, followed by hing (58.25%), cooking oil (57.18%) and linseed oil (55.24%) respectively

Foes can be friends: laboratory trials on invasive apple snails, Pomacea spp. preference to invasive weed, Limnocharis flava (L.) Buchenau compared to rice, Oryza sativa L.

Rice ecosystem often involves a complex interaction of various pest species with rice. An example of such interaction is that between the invasive Pomacea spp. and Limnocharis flava. Both invasive pests have caused heavy loss to rice in Southeast Asia including Malaysia. However, information on the interaction of both invasive pests in the rice field is still lacking. Therefore, a laboratory study was conducted to determine the feeding preference and growth pattern of P. canaliculata and P. maculatafor rice and L. flava based on choice and no-choice experiments. It was found that the three different sizes (1, 2 and 3cm) of both Pomacea spp. used in this study showed significantly less preference for rice stems and leaves as compared to L. flava leaves and stems. Among all the studied plant materials, rice stems were the least consumed. Moreover, higher shell length growth and weight gain was also recorded in the two species when fed with L. flava. This further suggests that the two Pomacea spp. have the potential to be used as an effective bio-control agent against the invasive weed in the rice ecosystem during the early stages of rice growth, in combination with a proper management of irrigation water. In addition, L. flava can also be used as a trap crop in rice fields to ease the collection and destruction of apple snails

Performance of pheromone and light traps in monitoring and management of tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae)

Tuta absoluta is an invasive, oligophagous pest that has been recently reported from Pakistan. Although originated from South America, it has now introduced and spread in almost all the tomato growing areas of the globe including Pakistan. Therefore, delta type pheromone traps containing synthetic 0.8 mg pheromone along with various colored light traps i.e., red, blue, golden, white, and green were evaluated for the monitoring and management of T. absoluta. Weekly observations were taken for the mean capture of T. absoluta moths in traps along with mean infestation percentage on leaves, stems and fruits of tomato. Results indicated that all the traps were found effective to attract T. absoluta moths, but they vary in their effectiveness to capture moths. Pheromone traps capture only males, whereas light traps attracted both the sexes. Significantly the highest number of males were captured in female synthesized pheromone traps, followed by golden color light traps, whereas red color light traps capture least number of males. Males captured in blue, white, and green color light traps were not significantly different from each other. Significantly the highest number of females were captured in golden color light traps, followed by blue color trap, whereas females capture in white and green color light traps were not significantly different from each other. The least number of females were captured in red color light traps. The tomatoes grown in golden color light and pheromone traps significantly suffered the lowest infestation, followed by blue, white, and green color light traps, whereas maximum damage was observed in red color light trap treatment. Only temperature showed a significant but very weak influence on the performance of various traps to attract T. absoluta moths. Therefore, studies should be undertaken to evaluate various combination of light traps with pheromone to maximize the capture T. absoluta moths, that could not only help in its early monitoring and detection but could lead to its mass destruction

Population Fluctuation and Damage Potential of Red Flour Beetle on Different Dry Fruits under Laboratory Conditions

The study was conducted to determine the population fluctuation of red flour beetle Tribolium castaneum on different dry fruits under laboratory conditions from 6th March 2015 to 24th July 2015. Four different dry fruits viz; T1 (almonds), T2 (walnuts), T3 (peanuts), T4 (cashew nuts) and T5 (wheat as control) were used in the experiment. The standard weight of 50g of every dry fruit was kept in plastic jars and covered with muslin cloth. Ten pairs of beetles were released in each jar. Observations were recorded at fortnight interval and population of the live beetles was counted. Results of the study showed that the population of red flour beetles gradually increased in all the treatments control with respect to time. The highest overall mean population of T. castaneum was recorded in wheat (61.61±10.02) followed by cashew nuts (52.90±8.26), almonds (50.01±7.81) and walnuts (43.56±5.89). The lowest population of red flour beetles (27.41±8.26) was recorded in peanut. The highest weight loss was recorded in wheat (18.8 %), followed by cashew nuts (15.6%), almonds (14%), walnuts (11.2%) and peanuts (8%) respectively