Prevalence of an Entomopathogenic Fungus, Hirsutella citriformis on Leucaena Psyllid, Heterapsylla cubana, in Malaysia

The leucaena psyllid, Heteropsylla cubana Crawford (Homoptera: Psyllidae) is a serious exotic pest of Leucaena leucocephala (Lam.) (Leguminosae) in Southeast Asia, Pacific Islands, Hawaii and Australia. Even though the insect is already widespread throughout Malaysia, no information on the entomopathogens associated with this pest has been recorded. This study reports, for the first time, the occurrence of an entomopathogenic fungus, Hirsutella citriformis Speare (Deuteromycotina: Hyphomycetes) on the leucaena psyllid, H. cubana in Malaysia. Results from monthly sampling of the psyllid over a period of one year established that the leucaena psyllid, H. cubana was susceptible to infection by the fungus, H. citriformis. Dead psyllids were found mummified and cemented by cream-coloured mycelia to the leaves and branches of the leucaena plant. The results also showed that adult psyllids were more prone to fungal infection than nymphs. The adult population had an average infection rate of about 20% while nymphs had an infection rate of less than 2%

The influence of time of infection on transovarial transmission of Nosema pyrausta (Paillot) in Ostrinia nubilalis (Hübner), and impact of transovarially infected eggs on an egg parasitoid and a predator

Nosema pyrausta (Paillot) detrimentally affects the development of its host the European corn borer, Ostrinia nubilalis (Hubner). Larvae exposed during the first two instars to 100 to 800 spores per mm(\u272) diet surface for 48 hours failed to pupate or emerge as morphologically normal adults. Infections of the later instars reduced the female adult longevity by 2 days and fecundity by at least 50%. The overall rate of transovarial infection increased by 15% when the spore concentrations were increased by a factor of eight. Also, the infection in the eggs increased from 37 to 54% from day 1 to day 7 of the ovipositional period. The pattern of infection in the eggs and subsequent larvae was similar, however, it was 18% higher in the larvae;Histological studies show that all parts of the reproductive organs, regardless of the stage of development, were susceptible to infection by N. pyrausta. In immature ovaries, the microsporidium infected the epithelial cells, stroma and germ cells. This infection subsequently spread to follicle cells and finally to the yolk;Nosema pyrausta detrimentally affected Trichogramma nubilale Ertle and Davis, decreasing the number of parasitoid adults emerging from infected hosts by 36% and the fecundity of these adults by 41%. The microsporidian spores, which were confined to the gut lumen in the larval stage, caused extensive infection in the gut epithelial, connective, neural and muscle tissues of the pupal and the adult stages;Chrysoperla carnea (Stephens) larvae fed N. pyrausta-infected eggs consumed the same number of prey compared to those of chrysopids fed uninfected eggs. They developed normally and were able to produce adults with unimpaired fecundity, fertility and longevity. The spores remained in the midgut throughout the larval feeding period and were eliminated in meconium during imaginal eclosion. At this time the spores had been within C. carnea for at least 7 days however, the spores maintained virulence in bioassays against European corn borer larvae

Histopathology of Metarhizium anisopliae, an Entomopathogenic Fungus, Infection in -the Termite, Coptotermes curvignathus

WOThers of the termite, Coptotermes curvignathus (IsofJtera: Rhinotermitidae), apestofmany tree crops including fruit and plantation trees, were inocttlated with the ento mopathogenic fungus, Metarh izium an isopliae byexfJosing the termite to viable conidia in a pet-Ii dish. The ontogeny of the fungus was followed histologically. Conidia which landed on the cuticle germinated within 24 h. The germ tube penetrated the cuticle and the hyphae subsequently invaded the tissues in the following order:fat body, muscles, neural, gut epithelial cells and gizzard. Infected termites died between 36- 48 h post-inoculation. Complete colonization of the tennite, however was not histologically evident until 72 h post-inoculation. At this stage, all parts of the insect '5 internal organs were infected. At 100 h, whitish mycelia began to emerge from the cuticle. Compacted masses of conidiophore1J'fOducing-green conidia were formed 120 h post-inoculation

Responses to Wood and Wood Extractives of Neobalanocarpus heimii and Shorea ovalis by the drywood termite, Cryptotermes cynocephalus (Isoptera : Kalotermitidae)

Drywood termites, Cryptotermes cynocephalus Light, were exposed to wood blocks and wood extractives of Neobalanocarpus heimii King and Shorea ovalis' Korth.} Bl. The results showed that the termites' survival and wood consumption were significantly higher on S. ovaHs than on N. heimii. Termite survival and feeding response obtained on bioassays with sawdust, extracted sawdusts and extract treated filter paper, indicated that one factor affecting the variation in relative susceptibility of the woods to termite attack could be secondary compounds present in the wood

Composition and abundance of collembola in primary and logged over forest.

The composition and abundance of collembola among three different forest habitats of the Sungai Lalang Forest Reserve, Selangor Malaysia were compared.The three forest habitats selected were primary forest,5-year old logged over forest(LOF) and 10-year old LOF. Result shows that primary forest had higher total number of Collembola as compared to that of LOF. Members of the entomobryidae had the most number of individual while onychiuidae, and isotomidae was found only in 5-year old LOF. Result of this study implies that primary forest conditions have a significant impact on abundance and composition of collembola communities

Attractant and phagostimulant effects of aqueous extract of cassava, Manihot esculenta, tuber on Coptotermes curvignathus and Coptotermes gestroi (Isoptera: Rhinotermitidae)

Effects of aqueous extracts of cassava tuber, Manihot esculenta, were evaluated on subterranean termites, Coptotermes curvignathus and Coptotermes gestroi (Isoptera: Rhinotermitidae). The termites were exposed to filter papers that had been treated with various concentrations of aqueous extract of cassava, and their responses to the treated papers in terms of their consumption, survival and attractiveness were compared with those of untreated papers. The results show that C. curvignathus and C. gestroi significantly preferred papers that had been treated with 10% and 5% of cassava tuber extract, respectively. Both termite species were significantly attracted to and consumed more treated papers than the untreated papers. Survival rates in treated groups were slightly lower than those in the control, but they were not significantly different. However, the termites survived poorly on papers that had been treated with cassava tuber extract higher than 15% concentration. This could be due to intoxication caused by cynogenic glycosides present in the cassava

Effects of food plants on development of spirama retorta (Lepidorptera: Noctuidae)

Development of Spirama retorta (Lepidoptera: Noctuidae) larvae fed on foliage of three Acacia spp., namely A. mangium, A. auriculiformis and A. crassicarpa, and Paraserianthes falcataria was assessed in the laboratory. The larvae did not survive when fed on either A. crassicarpa or P. falcataria. More than 64% reached pupal stage when fed on A. auriculiformis and A. mangium. The larval period was completed in 22.10 and 24.83 days when the larvae fed on A. auriculiformis and A. mangium foliage, respectively. The average pupal period was 10.51 and 11.32 and, the resulting adults lived for 36.51 and 37.94 days on A. auriculiformis and A. mangium, respectively. Even though the overall development variables were not significantly different, females from larvae fed A. auriculiformis had a significantly higher fecundity than those females from A. mangium. A total of 412 eggs// was recorded from those fed A. auriculiformis as compared to 255 eggs on A. mangium. This study thus shows that foliage of A. auriculiformis and A. mangium provided a suitable diet for s. retorta larvae. As such, these species may serve as alternative food resources important in the population dynamics of the moth in the absence of indigenous host plants