TL;DR: Three species of Lasiocampidae with social, tent-building caterpillars in Northern Bavaria are studied, showing markedly different life-history and behavioral strategies and the evolution and diversification of caterpillar sociality.
Abstract: We studied three species of Lasiocampidae with social, tent-building caterpillars in Northern Bavaria, viz. Eriogaster lanestris, Eriogaster catax, and Malacosoma neustria. We used key life-history data (number of larval instars, sizes and weights of eggs, caterpillars, and moths, size of egg clutches) as well as behavioral data (activity patterns, tent-building behavior, trail following behavior) for a comparative study. Although larvae of all three species are active only in spring, show overlapping habitat requirements, and use the same major host-plant (Prunus spinosa) with only minor differences in phenology, they show markedly different life-history and behavioral strategies.
E. catax lays comparatively few but large eggs while E. lanestris lays more but smaller eggs. M. neustria lays the smallest eggs but large clusters. E. lanestris caterpillars build a large tent with an accessible interior while those of E. catax build a small tent that is only used as a resting and molting platform. M. neustria shows a flexible behavior, may abandon the primary tent and build a new one several times. M. neustria colonies also subdivide and reunite regularly while Eriogaster colonies stay together until larvae become solitary. In E. lanestris all tentmates of a colony are highly synchronized while foraging or resting. Instead, in E. catax small subgroups leave the tent for foraging while at every time the majority rests on the tent. M. neustria caterpillars forage more or less individually and only synchronize by night. Results are discussed in relation to other species of the genera Eriogaster and Malacosoma and with regard to the evolution and diversification of caterpillar sociality.
TL;DR: The messy situation that resulted from the chaotic and whimsical ways of pouring chemical pesticides against apple pests in Lebanon, led to the development of an integrated pest management program of almond enemies, based on an extended biological and ecological studies of the injurious species in the local almond ecosystem.
Abstract: The messy situation that resulted from the chaotic and whimsical ways of pouring chemical pesticides against apple pests in Lebanon, led to the development of an integrated pest management program of almond enemies, based on an extended biological and ecological studies of the injurious species in the local almond ecosystem. The results of these studies were already reported in the seven previous parts of this series of papers.
The developed program aims at the reduction of pest populations through the application and integration of a number of useful cultural practices together with an absolute minimum of pesticidal treatments. Only pesticides of strictly selective nature are recommended, and their use is restricted to cases where no other alternative control measure was found satisfactory.
Where this program is followed, the discontinued application of contact pesticides leads, with time, to the repopulation of the almond ecosystem with its original useful fauna, at present much impoverished by the repeated applications of highly toxic chemicals. Once the natural enemies are re-established, a number of released secondary pests, like the now very serious Didesmococcus unifasciatus, will return to their former unimportant status.
Zusammenfassung
Beitrage zur Kenntnis der Mandelschadlinge in den ostlichen Mittelmeerlandern. VIII. Aufstellung des Programmes einer integrierten Bekampfung der Mandelschadlinge im Libanon
Die misliche Situation, die aus einer ungeregelten Anwendung rein chemischer Verfahren gegen Apfelschadlinge im Libanon resultierte, fuhrte zur Entwicklung eines integrierten Bekampfungsprogrammes gegen Mandelschadlinge. Es basiert auf grundsatzlichen biologischen und okologischen Untersuchungen uber die Bedeutung der verschiedenen Schadlinge fur das Okosystem. Die Ergebnisse dieser Studien wurden bereits in den ersten sieben Teilen der vorliegenden Serie dargestellt. Das auf diesen Ergebnissen aufbauende Bekampfungs-Programm hat zum Ziel, die Schadlingspopulationen mittels einer Reihe von Kulturverfahren in Verbindung mit einem Minimum an chemischer Bekampfung zu reduzieren. Bei letzterer kommen nur selektiv wirkende Praparate zur Anwendung, und auch dies nur in solchen Fallen, wo keine andere Moglichkeit besteht. Die Befolgung dieses Programms fuhrt nach kurzerer oder langerer Zeit zur Regeneration des Okosystems, insbesondere der Nutzlingsfauna, die z. Z. infolge der wiederholten Ausbringung starker toxischer Praparate verarmt ist. Sobald die naturlichen Schadlingsfeinde sich wieder stabilisiert haben, wird eine Anzahl sekundarer Schadlinge wie die z. Z. sehr schadliche Schildlaus Didesmococcus unifasciatus zu ihrem fruheren wenig schadlichen Status zuruckkehren.