Marking Adult Colorado Potato Beetles, \u3ci\u3eLeptinotarsa Decemlineata\u3c/i\u3e (Coleoptera: Chrysomelidae) Using Paper Labels

The smooth elytra of adult Colorado potato beetle, Leptinotarsa decemlineata, make this insect difficult to make efficiently for long-term field studies. Enamel paint marks fell off rapidly, and after 28 days, 25010 of marked beetles had lost all four original marks. Use of small paper labels glued to the elytra after an acetone wash and sanding pretreatment was the most effective method for long term marking of individual beetles. Mortality in labeled laboratory-reared and field-collected beetles did not increase when compared to unmarked beetles

Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) Observed Feeding on Chamaesaracha sp. in Eastern Colorado.

Egg, larval, and adult life stages of Colorado potato beetle, Leptinotarsa decemlineata (Say), were observed feeding on or attached to a previously undocumented host plant belonging to the genus Chamaesaracha in eastern Colorado on July 2017. At one site, L. decemlineata were more abundant on Chamaesaracha sp. than the accepted ancestral host plant, Solanum rostratum (Dunal). While future studies should confirm the ancestral status of the observed L. decemlineata and suitability of Chamaesaracha sp. for completion of development, our observations suggest a need for further characterization of the ancestral host range of L. decemlineata

Movement of Adult Colorado Potato Beetles, \u3ci\u3eLeptinotarsa Decemlineata\u3c/i\u3e (Coleoptera: Chrysomelidae), in Response to Isolated Potato Plots

Mark recapture techniques were used to determine Colorado potato beetle movement in circular arenas with isolated plots of potatoes at each ordinal direction. Post-diapause beetles aggregated on one or a few of the plants in one of the plots for each release, but not on the same plants in different releases. Differences in plant attractiveness were therefore not likely responsible for the aggregatory behavior. Aggregations were probably a result of either coordinated movement from the release site to the plants or an aggregatory signal with a range of at least 15 m. Summer adults did not aggregate on plants. Correlations of summer beetle recapture distributions to wind direction showed that anemotactic behavior could not account for the major portion of variation in beetle orientation to the potato plots. Some positive attraction to the plots was indicated because more beetles were recaptured at the plots than would be expected from random motion. The number of beetles recaptured at plots covered by cheesecloth was not significantly different from recaptures on uncovered plots, indicating little reliance on visual cues specific to potatoes for location of the plants

Movement, Dispersion, and Orientation of a Population of the Colorado Potato Beetle, \u3ci\u3eLeptinotarsa Decemlineata\u3c/i\u3e (Coleoptera: Chrysomelidae), in Eggplant

Short-term dispersal, dispersion, and orientation of a population of the Colorado potato beetle, Leptinotarsa decemlineata. were examined in a uniformly spaced planting of eggplant using a mark-recapture technique. Recaptures of marked beetles declined throughout the study, the greatest decline occurring 24 h after release. Dispersal of remaining beetles through the field was gradual; beetle numbers declined with distance from the release point during the first 3 days of the study and increased with distance thereafter. Beetles were highly aggregated for 3-4 days after release but were well dispersed for the remainder of the study. Dispersal of aggregated beetles may have been stimulated by host plant defoliation. Orientation of dispersing beetles was significantly nonrandom for the majority of the study. Beetles oriented predominantly east-northeast

Exploitation of Eggs of the Colorado Potato Beetle, \u3ci\u3eLeptinotarsa Decemlineata\u3c/i\u3e (Coleoptera: Chrysomelidae), by the Exotic Egg Parasitoid \u3ci\u3eEdovum Puttleri\u3c/i\u3e (Hymenoptera: Eulophidae) in Eggplant

Edovum puttleri is a newly discovered, exotic, egg parasitoid of the Colorado potato beetle, (CPB) Leptinotarsa decemlineata. The exploitation of CPB eggs by E. puttleri was examined in a New Jersey eggplant field. E. puttleri parasitized 46.8% of the CPB eggs present in the field. Exploitation of eggs within eggmasses was high; 73.9% of CPB eggs in eggmasses attacked by E. puttleri were parasitized

Preparatoirs for potatoes in organic farming

The aim of this experiment was to try alternative methods of regulation of Colorado beetle (Leptinotarsa decemlineata) and late blight (Phytophthora infestans) (the biggest harmfull organisms of potatoes) and production of the good-class of the biopotatoes. Preparation Neem-Azal showed trend of the lower larvae occurence. Combination of the cupric fungicide with preparation PRP-EBV and vermicompost decreased tops-attack by late blight. The statistically lowest production was under the scaffold net. There were not found significant differences in production by using vitality- strengthening preparation

Regulation of the juvenile hormone titre in the Colorado potato beetle

Three main topics were investigated in regulation of the titre of juvenile hormone in haemolymph of the Colorado potato beetle ( Leptinotarsa decemlineata Say): enzymic breakdown of the hormone; binding and protection of the hormone by carrier proteins; the synthetic capacity of the corpora allata.Juvenile hormone was broken down by two major pathways: ester hydrolysis by esterases and hydration of the epoxide group by epoxide hydratases in tissue. In haemolymph of the beetle, juvenile hormone is solely broken down by juvenile hormone esterases. An in vitro method was developed to measure the catalytic activity of juvenile hormone esterase from haemolymph. High activities were observed in fourth-instar larvae and in beetles just before diapause. Lower activities were found in third- instar larvae and in beetles reared with long days, at diapause and after diapause. The juvenile hormone esterase was insensitive to diisopropylfluorophosphate (DFP), an inhibitor used to distinguish between carboxylesterases and esterases specific to juvenile hormone. Electrophoresis of the esterase from haemolymph showed one or more esterases specific to juvenile hormone.The short half-life of juvenile hormone measured in vivo and in vitro in the haemolymph and inhibition studies with Triton X-100 suggests that juvenile hormone esterases in haemolymph govern breakdown. Activities of juvenile hormone esterase correlate well with the juvenile hormone titre.The sharp changes in juvenile hormone esterase suggest that esterase activity is regulated. The mechanism was studied by supplying juvenile hormone and by microsurgery. Treatment of diapausing beetles with juvenile hormone itself or analogues caused an increase in activity of juvenile hormone esterase within 24 h. Ligation or removal of corpora allata suggested that this induction was an indirect effect of juvenile hormone. Transfer from short day to long day and treatment with hormone of beetles reared with short days prevented high activity of juvenile hormone esterase. Removal of corpora allata at emergence from beetles reared with short days resulted in the same. In beetles reared with short days the titre of hormone during the first days after adult emergence probably induces the rise in esterase. Esterase activity is thus most likely controlled indirectly by the hormone, via a centre in the brains (hormostate). The level of esterase activity is probably dependent on the sensitivity of this hormostate and on the titre of the juvenile hormone.In several insects juvenile hormone is transported bound to carrier proteins. In haemolymph of larval and adult Colorado potato beetles lipoproteins of high molecular weight (>100,00 daltons) were found, capable of binding juvenile hormone, its analogues, and palmitic acid. The lipoproteins were partially separated by gel permeation chromatography and electrophoresis on polyacrylamide gel. The binding characteristics of the lipoproteins indicate low affinity (K d ≈10 -5 M), low specificity and high binding capacity. The juvenile hormone complexed to lipoproteins was protected against esterases from haemolymph to some extent. Thus these carrier lipoproteins probably play little role in the regulation of the titre of juvenile hormone.In the last part of our investigations the activity of the corpora allata was measured in vitro. High activities were observed in beetles reared with long days and in beetles after emergence. In beetles reared with short days, amounts of hormone produced were intermediate until Day 6 after emergence, thereafter declining to a low value. During diapause, production remained low. The production by corpus allatum and the activity of juvenile hormone esterase were in good agreement with the titre of juvenile hormone. The corpora allata are probably the primary regulator of the hormone titre in the Colorado potato beetle.<p/

Effect of \u3ci\u3eBeauveria Bassiana\u3c/i\u3e on Underground Stages Of the Colorado Potato Beetle, \u3ci\u3eLeptinotarsa Decemlineata\u3c/i\u3e (Coleoptera: Chrysomelidae)

Tests were conducted to determine the effect of the fungus Beauveria bassiana (B.b.) on underground of the Colorado potato beetle (CPB), Leptinotarsa decemlineata. Two levels of B.h., g/m2 and 75 g/m2 , were suspended in water and sprinkled over the surface of the ground in cages to which CPB were added, either as overwintering adults or as 4th instar larvae of the 15t generation. Efficacy of treatments was determined by counting emerged adults. Neither level of B .b. increased mortality in overwintering adults. The highest level of B.h. caused a significant decline in emergence of adults from the 1st generation 4th instars. The 7.5 g/m2 treatment level did not significantly differ from control treatments

The Influence of Plant Dispersion on Movement Patterns of the Colorado Potato Beetle, \u3ci\u3eLeptinotarsa Decemlineata\u3c/i\u3e (Coleoptera: Chrysomelidae)

The influence of plant dispersion on movements of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), was studied with mark-recapture techniques. Beetles released between potato monocultures, polycultures with two additional non-host plant species, and polycultures with five additional non-host species, randomly colonized the three types of plots. Releases between different arrangements of potted host and non-host plants showed (1) greater beetle colonization and greater length of time spent on potato plants growing alone than on potato plants surrounded by non-host vegetation, and (2) no effect of potato plant density on colonization or tenure time. Overall, there was a 65~ recapture rate; beetles consistently stayed on the same plants they originally colonized, often for at least five days after release

ALTERNTIVE PROTECTION OF BIOPOTATOES IN ORGANIC FARMING

There were tested water extracts from Syringa vulgaris and Pyrethrum parthenium. They did not prove significant differences of decrease of the air attack of Colorado potato beetle (Leptinotarsa decemlineata), the activity of eggs – laying and the occurrence of larvae in comparison to the control. Interesting trends of lower-eggs lying and a lower larvae occurrence were discovered. The liquid spray against the late blight (Phytophthora infestans) did not significantly decrease neither occurrence of late blight or the yield. The production of the bio-potatoes is only 0,2 % of all potatoes production in the Czech Republic. The aim of this experiment was to try alternative methods of regulation of Colorado potato beetle and late blight (the biggest harmfull organisms of potatoes). For biological agriculture could be also suitable water extracts. These are possible to use as protection of potatoes against unfavorable factors (Colorado potate beetle and late blight) and increase yield and quality of production