Philip B. Taylor

Parasitoids Attacking the Emerald Ash Borer (Coleoptera: Buprestidae) in Western Pennsylvania

ABSTRACT Field surveys of the emerald ash borer (EAB), Agrilus planipennis Fairmaire, and associated parasitoids were conducted in Cranberry Township, PA from 11 Mar to 23 Oct 2008. Several species of parasitic Hymenoptera were collected from EAB-infested green ash trees or reared from late-instar EAB larvae, prepupae, and/or pupae. These included Balcha indica (Mani & Kaul), Eupelmus pini Taylor (Eupelmidae), Dolichomitus vitticrus Townes (Ichneumonidae), and 2 additional unidentified ichneumonids, Orthizema sp. Townes and Cubocephalus sp. Townes. Together, these parasitoids caused about 3.6% parasitism of EAB in the field. The most abundant species was B. indica accounting for 82% of all parasitoids recovered during our survey. Subsequent laboratory assays confirmed that B. indica and E. pini are solitary ectoparasitoids of EAB larvae, prepupae, and/or pupae. In addition, both B. indica and E. pini reproduce through thelytokous parthenogenesis; i.e., virgin females produce daughters. These parasitoids may be complementary to current classical biological control programs against EAB in North America, which have been focusing primarily on the introduction of exotic larval and egg parasitoids from China.

Parasitoid Guilds of Agrilus Woodborers (Coleoptera: Buprestidae): Their Diversity and Potential for Use in Biological Control

Literature studies in North America (US and Canada), Europe, and Asia (particularly Russia, China, Japan, and the Korean peninsula) were reviewed to identify parasitoid guilds associated with Agrilus woodborers. There are at least 12 species of hymenopteran parasitoids attacking eggs of Agrilus beetles and 56 species (36 genera), attacking Agrilus larvae infesting various host plants in North America, Asia, and Europe. While most of the egg parasitoids (9 species) belong to the family Encyrtidae, a majority of the larval parasitoids are members of five families: Braconidae (24 species/11 genera), Eulophidae (8 species/4 genera), Ichneumonidae (10 species/9 genera), and Eupelmidae (6 species/5 genera). The highest rate of Agrilus egg parasitism (>50%) was exerted by encyrtid wasps (4 species) in North America, Asia, and Europe. In contrast, the highest rate of Agrilus larval parasitism (>50%) was caused by species in two genera of braconids: Atanycolus (North America) and Spathius (Asia), and one eulophid genus, Tetrastichus (Asia and Europe). Reported rate of Agrilus larval parasitism ichneumonids was frequent in North America, but generally low (<1%). Potential for success in biological control of emerald ash borer (Agrilus planipennis Fairmaire) in the USA with North American native parasitoids and old-association Asian parasitoids is discussed.

Hymenopteran Parasitoids Attacking the Invasive Emerald Ash Borer (Coleoptera: Buprestidae) in Western and Central Pennsylvania

ABSTRACT We conducted field surveys of the emerald ash borer (EAB), Agrilus planipennis Fairmaire, and associated larval parasitoids in western and central Pennsylvania (Cranberry Township in Butler County and Granville in Mifflin County) in the spring and fall of 2009. The survey procedure involved destructively debarking sections of the main trunk (bole) of EAB-infested green ash (Fraxinus pennsylvanica Marsh.) trees from the ground to the height of 2 m. Three species of the hymenopteran parasitoids were consistently recovered from EAB larvae observed in both survey sites, including two indigenous species of braconids, Spathius laflammei Provancher (= Spathius benefactor Matthews) and Atanycolus nigropyga Shenefelt and the exotic (accidentally introduced) eupelmid Balcha indica (Mani & Kaul). In addition, there are three unidentified species of hymenopteran parasitoids including two braconids Atanycolus sp. [possibly Atanycolus disputabilis (Cresson)] and Spathius sp. (at the Butler Co. site) and one ichneumonid Dolichomitus sp. (at the Mifflin Co. site). These parasitoids together parasitized 0.5–4.6% and 0.5–1.5% of the sampled EAB hosts at the Butler and Mifflin Co. sites, respectively. Parasitism rate by each species or group of those hymenopteran parasitoids varied between the two survey sites—with parasitism rates being generally higher at the Butler Co. site than at the Mifflin Co. site. Studies are needed to determine if those new associations of North American indigenous braconid parasitoids with EAB may play a complementary role in controlling this invasive pest.

Biology and Life History of Balcha indica, an Ectoparasitoid Attacking the Emerald Ash Borer, Agrilus planipennis, in North America

Abstract Balcha indica Mani and Kaul (Hymenoptera: Eupelmidae) is a solitary ectoparasitoid attacking larvae, prepupae, and pupae of the emerald ash borer, Agrilus planipennis Fairmaire (Hymenoptera: Eupelmidae). Its fecundity, oviposition rate, longevity, and development time were determined in the laboratory under standard rearing conditions (25 ± 2° C, 65 ± 10% relative humidity, and 14:10 L:D). Adults lived a mean of 59 days with a maximum of 117 days. Lifetime adult fecundity averaged 36 eggs with a maximum 94 eggs per female. The egg stage lasted for a maximum of four days with ∼ 50% eggs hatched within two days. The development time of the first instars lasted for a maximum of nine days; 50% of the first instars completed their development (i.e., molted to the next instar) within five days. Instars of the intermediate and final stage larvae (after molting of the first instars occurred) could not be distinguished until they reached the pupal stage, and 50% of those larvae pupated ∼ 62 days after adult oviposition. Under the standard rearing conditions, 50% of B. indica took ∼ 83 days to complete the life cycle (from egg to adult emergence) ranging from 47 to 129 days. These results suggest that B. indica may not have more than two generations in the mid-Atlantic and Midwest regions of United States, where normal growing seasons—with average temperature above 25° C—are normally less than six months (May–October). Because of the long life span and oviposition period of adults, however, B. indica is likely to have overlapping generations.

Current Distribution and Historical Range Expansion of Calosoma sycophanta (L.) (Coleoptera: Carabidae) in North America

Since the intentional introduction, release, and establishment of the lymantriid predator, Calosoma sycophanta (L.), in 1906–07 in the vicinity of Boston, MA, its range has continued to expand. Com...