Associate Professor and Associate Chair State University of New York Oswego, New York
The bog buckmoth (Hemileuca sp.) is an endangered saturniid found in peatlands and known only from ten sites around the North American Great Lakes. Populations have declined in recent years, and some have disappeared. The egg parasitoid Anastatus furnissi (Eupelmidae) may be an important mortality source. I report on a decade of study of parasitoid and host in New York, assessing A. furnissi impact and observing its life cycle and behavior in the field. Bog buckmoth oviposition behavior is unusual: it oviposits not on the larval food plant (Menyanthes) but on plants nearby. I recorded the plant species on which I found egg clusters, plus height, distance from Menyanthes, cluster size, and attack rate of emerging parasitoids, and found that these parameters varied between sites. Nonetheless, parasitism averaged 10-20% across years and sites regardless of host density, suggesting that A. furnissi is a significant mortality source but not density dependent and unlikely the cause of extirpations. I found no consistent relationships between parasitism rates and plant species or egg cluster height or size. Parasitized clusters were usually closer to Menyanthes than were unparasitized eggs, suggesting that the plants are used to find hosts. Both parasitoid and host oviposit in fall and emerge in spring, but as the moth is univoltine it is likely that A. furnissi uses other hosts in summer. These findings suggest that A. furnissi is an opportunistic parasitoid of saturniid eggs and able to utilize hosts in varied habitats.
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