Abstract Colorado potato beetles have been reared successfully through 12 generations on artificial diets containing either 2.5% potato leaf powder or 2.5% lettuce leaf powder/0.75% potato leaf powder. For all but one of the treatment groups, the mean duration of each of the four larval stages was between 0.8 and 1.5 days longer than the durations exhibited by control beetles that had been fed on potato leaves. Maximum weights of prepupae, newly emerged adults and day 5 – 9 adults were approximately 78, 80 and 82%, respectively, of the weights for comparable stages of control beetles. Mean percent mortality for 1st instars was two to six times higher for artificial diet-fed CPBs than for leaf-fed beetles. However, since pupal mortality was four times higher for control beetles than for beetles reared on artificial diet, mean percent total mortality (newly hatched through the 9 day old adult) was equivalent for leaf-fed beetles and for later generations of potato and Lettuce+Potato diet-fed CPBs. Hemolymph ecdysteroid levels and fluctuations in mature 4th instar larvae and prepupae were similar in controls and experimental groups. Number of hatchlings produced per adult pair per day (fertility) was approximately eight times greater in control beetles than in later generations of artificial diet-fed beetles, primarily because fewer egg masses were laid per day, percent hatch was lower and cannibalism of eggs was higher in these latter groups. Interestingly, the mean percent hatch, although only 68% of the control value, was 1.5 times greater for beetles reared on diet containing lettuce-leaf powder, and a small percentage of potato leaf powder, than on diet containing only potato leaf powder. Percent hatch was equal for beetles fed on diet containing only lettuce-leaf powder and those fed on potato leaves. Finally, it is noteworthy that the quality of eggs, as judged by the ability of the wasp parasitoid, Edovum puttleri, to parasitize and develop in the eggs, was similar for eggs produced by control beetles and for those produced by beetles fed on potato and Lettuce+Potato diets. The diets and rearing system described here will be useful for providing beetles on a year-round basis for experiments designed to evaluate the effects of potential insect control agents, to investigate the mechanism(s) by which insects become resistant to control agents and for other applied and fundamental studies related to the control of this serious pest. The use of lettuce leaf powder in place of most of the potato leaf powder is especially advantageous because of the much reduced cost and greater availability of lettuce as compared to potato leaves.

The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is an agricultural pest of solanaceous crops which has developed insecticide resistance at an alarming rate. Up to this point, little consideration has been given to unintended, or inadvertent effects that non-insecticide xenobiotics may have on insecticide susceptibility in L. decemlineata. Fungicides, such as chlorothalonil and boscalid, are often used to control fungal pathogens in potato fields and are applied at regular intervals when L. decemlineata populations are present in the crop. In order to determine whether fungicide use may be associated with elevated levels of insecticide resistance in L. decemlineata, we examined phenotypic responses in L. decemlineata to the fungicides chlorothalonil and boscalid. Using enzymatic and transcript abundance investigations, we also examined modes of molecular detoxification in response to both insecticide (imidacloprid) and fungicide (boscalid and chlorothalonil) application to more specifically determine if fungicides and insecticides induce similar metabolic detoxification mechanisms. Both chlorothalonil and boscalid exposure induced a phenotypic, enzymatic and transcript response in L. decemlineata which correlates with known mechanisms of insecticide resistance.

Steroidal glycoalkaloids, found in species of the Solanaceae, elicit bursting activity in galeal and tarsal chemosensilla of adult Colorado potato beetles. The effect has an average latency of 6-12 sec, depending on the sensillum/alkaloid combination. A 20-sec alkaloid treatment is often suffficient to render galeal sensilla unresponsive to gamma-aminobutyric acid, normally an effective stimulant. The alkaloids have similar effects on galeal sensilla of larval Colorado potato beetles and on labe

Колорадский жук Leptinotarsa decemlineata Say (Coleoptera, Chrysomelidae) является основным специализированным фитофагом картофеля и овощных пасленовых культур. В климатических условиях Ленинградской области вредитель ежегодно развивается в одной полной генерации, независимо от температур воздуха в течение летнего периода. Вследствие повсеместно высокой численности и вредоносности колорадского жука в России, культуры картофеля и баклажана требуют больших затрат сил и средств на проведение защитных мероприятий. Это повышает значение возделывания устойчивых к вредителю сортов данных культур. Устойчивость различных сортов растений к вредителю изучали в 2000–2022 годах на посадках картофеля в Ленинградской области и на опытном поле ВИЗР. В специальных полевых исследованиях ежегодно проводили искусственное заселение 15–20 сортов картофеля и 7–12 сортов баклажана личинками I возраста. В таких опытах устойчивые к вредителю сорта картофеля и баклажана отбирали по совокупности биоэкологических показателей продолжительности преимагинального развития особей, степени гетерохронии развития личинок, доле выживших личинок IV возраста и вышедших жуков по отношению к количеству подсаженных личинок I возраста. На полях с естественным фоном заселения колорадским жуком устойчивые сорта картофеля отбирали по показателям уровня численности вредителя во всех фазах и степени поврежденности растений. Показано, что устойчивые к вредителю сорта баклажана часто выявляются среди тех, которые принадлежат

Landscape-scale intensification of individual crops and pesticide use that is associated with this intensification is an emerging, environmental problem that is expected to have unequal effects on pests with different lifecycles, host ranges, and dispersal abilities. We investigate if intensification of a single crop in an agroecosystem has a direct effect on insecticide resistance in a specialist insect herbivore. Using a major potato pest, Leptinotarsa decemlineata, we measured imidacloprid (neonicotinoid) resistance in populations across a spatiotemporal crop production gradient where potat

Herbivores are squeezed between the two omnipresent threats of variable food quality and natural enemy attack, but these two factors are not independent of one another. The mechanisms by which organisms navigate the dual challenges of foraging while avoiding predation are poorly understood. We tested the effects of plant defense and predation risk on herbivory in an assemblage of leaf-chewing insects on Solanum lycopersicum (tomato) that included two Solanaceae specialists (Manduca sexta and Leptinotarsa decemlineata) and one generalist (Trichoplusia ni). Defenses were altered using genetic ma

substances to host plants. 3.3.4. Colorado potato beetle The Colorado potato beetle is an oligophagous insect … namely the Colorado potato beetle, Leptinotarsa decemlineata (Say) living on solanaceous plants, the … and Ryan (1972) report that Colorado potato beetle damage to tomato or potato leaves leads to an increase