Toby R. Petrice

Laboratory Evaluation of the Toxicity of Systemic Insecticides for Control of Anoplophora glabripennis and Plectrodera scalator (Coleoptera: Cerambycidae)

Abstract Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) is one of the most serious nonnative invasive forest insects discovered in North America in recent years. A. glabripennis is regulated by federal quarantines in the United States and Canada and is the subject of eradication programs that involve locating, cutting, and chipping all infested trees. Other control methods are needed to aid in eradication and to form an integrated management program in the event eradication fails. We conducted laboratory bioassays to determine the toxicity of two systemic insecticides, azadirachtin and imidacloprid, for potential control of A. glabripennis and the cottonwood borer, Plectrodera scalator (F.) (Coleoptera: Cerambycidae), a closely related native cerambycid. Larvae of both cerambycid species were fed artificial diet with dilutions of azadirachtin or imidacloprid for 14 wk. Both insecticides exhibited strong antifeedant effects and some toxicity against A. glabripennis and P. scalator larvae. For A. glabripennis, the highest larval mortality at the end of the bioassay was 60% for larvae fed artificial diet treated with azadirachtin (50 ppm) or imidacloprid (1.6 ppm). For P. scalator, the highest larval mortality at the end of the bioassay was 100% for larvae fed artificial diet treated with azadirachtin (50 ppm) or imidacloprid (160 ppm). At 14 wk, the LC50 values for P. scalator were 1.58 and 1.78 ppm for azadirachtin and imidacloprid, respectively. Larvae of both species gained weight when fed diet treated with formulation blanks (inert ingredients) or the water control but lost weight when fed diet treated with increasing concentrations of either azadirachtin or imidacloprid. In a separate experiment, A. glabripennis adults were fed maple twigs treated with high and low concentrations of imidacloprid. A. glabripennis adult mortality reached 100% after 13 d on twigs treated with 150 ppm imidacloprid and after 20 d on twigs treated with 15 ppm imidacloprid. There was no visible feeding by A. glabripennis adults on twigs treated at the higher imidacloprid rate, and feeding was significantly reduced for adults placed on twigs treated at the low imidacloprid rate compared with adults on untreated twigs. In summary, imidacloprid and azadirachtin had both antifeedant and toxic effects against A. glabripennis and P. scalator and have potential for use in management programs. Based on our results, the delivery of high and sustained insecticide concentrations will be needed to overcome the antifeedant effects and lengthy lethal time for both larvae and adults exposed to these insecticides.

Bark- and Wood-Borer Colonization of Logs and Lumber After Heat Treatment to ISPM 15 Specifications: The Role of Residual Bark

ABSTRACT Wood packaging material (WPM) is a major pathway for international movement of bark- and wood-infesting insects. ISPM 15, the first international standard for treating WPM, was adopted in 2002 and first implemented in the United States in 2006. ISPM 15 allows bark to remain on WPM after treatment, raising concerns that insects could infest after treatment, especially if bark were present. We conducted field studies to evaluate insect infestation of green logs and lumber with varying amounts of bark after heat treatment. In a log study, Cerambycidae and Scolytinae (ambrosia beetles and bark beetles) readily infested and developed in logs with bark after heat treatment. In a lumber study, Cerambycidae and bark beetles laid eggs in all sizes of bark patches tested (≈25, 100, 250, and 1,000 cm2) after heat treatment but did not infest control or heat-treated lumber without bark. Cerambycidae completed development only in boards with bark patches of 1,000 cm2, whereas bark beetles completed development on patches of 100, 250, and 1,000 cm2. Survival of bark beetles was greater in square patches (10 by 10 cm) versus rectangular patches (2.5 by 40 cm) of the same surface area (100 cm2). In surveys at six U.S. ports in 2006, 9.4% of 5,945 ISPM 15-marked WPM items contained bark, and 1.2% of 563 ISPM 15-marked WPM items with bark contained live insects of quarantine significance under the bark. It was not possible to determine whether the presence of live insects represented treatment failure or infestation after treatment.

Selection of Overwintering Sites by Tomicus piniperda (Coleoptera: Scolytidae) during Fall Shoot Departure

Selection of overwintering sites at the base of Scotch pine, Pinus sylvestris L., trees by Tomicus piniperda (L.) adults was monitored in northwestern IN. We monitored adult movement five times dur...

Two new species of Oobius Trjapitzin (Hymenoptera, Encyrtidae) egg parasitoids of Agrilus spp. (Coleoptera, Buprestidae) from the USA, including a key and taxonomic notes on other congeneric Nearctic taxa.

Abstract Oobius Trjapitzin (Hymenoptera, Encyrtidae) species are egg parasitoids that are important for the biological control of some Buprestidae and Cerambycidae (Coleoptera). Two species, Oobius agrili Zhang & Huang and Oobius longoi (Siscaro), were introduced into North America for classical biocontrol and have successfully established. Two new native North American species that parasitize eggs of Agrilus spp. (Buprestidae) are described and illustrated from the USA: Oobius minusculus Triapitsyn & Petrice, sp. n. (Michigan), an egg parasitoid of both Agrilus subcinctus Gory on ash (Fraxinus spp.) and Agrilus egenus Gory on black locust (Robinia pseudoacacia L.) trees, and Oobius whiteorum Triapitsyn, sp. n. (Pennsylvania), an egg parasitoid of Agrilus anxius Gory on European white birch (Betula pendula Roth). A taxonomic key and notes on the Nearctic native and introduced Oobius species are also included.