Evaluation of Experimental Populations and Glandular-Haired Varieties of Alfalfa for Alfalfa Blotch Leafminer (Diptera: Agromyzidae) Feeding Injury

Following the spread of the alfalfa blotch leafminer, Agromyza frontella (Rondani) (Diptera: Agromyzidae), into Minnesota and Wisconsin U.S.A. during 1994-1997, three field trials were conducted in Minnesota to assess the potential for leafminer resistance among several sources of alfalfa (Medicago sativa), germplasm. In 1998, 86 entries were evaluated, most of which were experimental populations. In addition, six commercial varieties of alfalfa were evaluated. Of the six varieties, four had been bred for various levels of glandular-hair expression, specifically for resistance to the potato leafhopper, Empoasca fabae (Harris) (Homoptera: Cicadellidae). In two of three trials, we found no significant differences in leafmining injury to trifoliolates among the 86 entries, or among glandular-haired and traditional commercial varieties. At one location, ‘Arrest,’ ‘Ameriguard 301,’ and ‘DK 121 HG’ incurred significantly less pinhole injury than the glandular-haired variety ‘5347 LH’ or the commercial standard, ‘5454.’ However, after accounting for both pinhole and leafmining injury, only ‘Arrest’ and ‘Ameriguard 301’ had less injury than ‘5347 LH,’ ‘DK 121 HG,’ or the standard ‘5454.’ The low levels of resistance to A. frontella injury, among glandular-haired commercial alfalfa varieties and numerous experimental populations M. sativa, confirm the need for alternative A. frontella management strategies such as biological control and possible manipulation of harvest schedules

New records of Agromyzidae (Diptera) from western Turkey

Specimens were collected once a week from Mugla province, western Turkey, in 2000 and 2001 from cultured and non-cultured plants. During this study Ophiomyia pulicaria (Meigen, 1830); Aulagromyza buhri (de Meijere, 1938); Chromatomyia scolopendri (Robineau-Desvoidy, 1851); Liriomyza flaveola (Fallen 1823); Liriomyza sativae Blanchard, 1938; Phytomyza angelicae Kaltenbach, 1872; Phytomyza conyzae Hering, 1920; Phytomyza rufipes Meigen, 1830; Phytomyza thysselinivora Hering, 1924 are newly recorded for the Turkish leafminer fauna. Morphological descriptions, hosts and their general distributions are given

New and Little-Known Agromyzidae from Michigan (Diptera: Acalyptratae)

The latest major work on North American Agromyzidae, The Agromyzidae of Canada and Alaska (Spencer, 1969), lists 290 regional species. Of that number, half (147) are new species and 23 are previously described species newly recorded for the continent. It is thus evident that the North American Agromyzid fauna is still poorly known. Among material recently determined for the collection of Michigan State University, East Lansing, were the 5 additional new species herein described. A male allotype for Melanagromyza inornata Spencer (1969), described from the female only, is also described, and more detailed figures of the male postabdomen of Melanagromyza lauta Spencer (1969) are presented. Unfortunately all of the material is from random collecting and no host plants for the species are known. Types are retained in the collections of the United States National Museum of Natural History (USNM) and paratypes are returned to the Michigan State University collections (MSC)

First Report of the Alfalfa Blotch Leafminer (Diptera: Agromyzidae), and Selected Parasites (Hymenoptera: Eulophidae) in Minnesota and Wisconsin, USA

Alfalfa blotch leafminer, Agromyza frontella, has been a serious pest of alfalfa, Medicago sativa, in the northeastern U.S. and in eastern Ontario, Canada. Until recently, the western edge of the A. frontella distribution in the U.S. was limited to eastern Ohio. We document for the first time, the occurrence of A. frontella in Minnesota and Wisconsin. Alfalfa stems damaged by A. frontella, based on adult feeding punctures, obvious blotched leafmining or the presence of larvae, were first found in 3 northern Minnesota coun­ties during October, 1994. Infested counties included Lake of the Woods, Cook and Lake, all bordering western Ontario, Canada. In 1995, A. frontella was again found in Cook and Lake counties, where 99-100% of the stems, and 18-35% of the trifoliates/stem, contained larvae or exhibited obvious feeding damage. In 1996, following a more expanded survey, a total of 11 and 5 counties, in Minnesota and Wisconsin, respectively, showed some level of A. frontella feeding damage (stem samples ranged from \u3c5 to 100% infested). Based on additional counties surveyed 11 October, 1996, where A. frontella was not found, we now have a reasonable estimate of the southern edge of the distribution in Minnesota and Wisconsin. A total of 2 and 6 A. frontella adults were identified from sweep-net samples taken from fields with obvious feeding damage during 1995 (Lake Co.) and 1996 (Cook Co,), respectively. Three eulophid (Hymenoptera) parasites were reared from A. frontella-infested alfalfa stems collected during October, 1994 in Cook Co., Minn., including: Diglyphus begini, D. pulchripes, and Diglyphus sp., prob. isaea, all of which are new records. Our hypothesis is that A. frontella moved into Minnesota from Ontario Canada, via alfalfa hay purchased by northern Minnesota growers

Distribution of an Exotic Pest, \u3ci\u3eAgromyza Frontella\u3c/i\u3e (Diptera: Agromyzidae), in Manitoba, Canada.

Agromyza frontella is an exotic alfalfa pest from Europe that was first detected in North America in 1968 and has since spread westward into Ontario and the north central United States. Informal surveys had detected A. frontella in Manitoba, but its distribution throughout this province was unknown. In 1998 we collected alfalfa stems to detect plant damage and sweep samples to detect adult A. frontella and the parasitoid Dacnusa dryas throughout the alfalfa growing region of Manitoba. In south central Manitoba, 100% of stems were damaged by A. frontella, and\u3e 100 adults/10 sweeps were recorded at several sites. In west central Manitoba, no plants were damaged and \u3c 10 adults/10 sweeps were observed. We believe this region to be near the western edge of A. frontella distribution. The most important introduced parasitoid of A. frontella, D. dryas, was not detected which suggests that D. dryas has not invaded Manitoba

Seasonal Abundance; Damage; and Comparison of Different Heights, Orientations, and Directions of Yellow Sticky Traps for Sampling of \u3ci\u3eLiriomyza Trifolii\u3c/i\u3e (Diptera: Agromyzidae) in Cotton

This study was done to determine the optimum height, orientation, and direction of yellow sticky traps for sampling of Liriomyza trifolii (Burgess) (Diptera: Agromyzidae) in cotton fields. Leaf infestation rates for the whole plants, as well as for each of three plant regions, and number of mines per infested leaf were also determined. Traps were placed at 25 cm above the plant canopy and 30 cm above the ground at two orientations (horizontal and vertical) and two directions (east-to-west and north-to-south) for each height and orientation in Aydin province, Turkey. Horizontally oriented traps captured more flies than vertically oriented traps. More flies were captured 25 cm above the plant canopy than 30 cm above the ground. The upper sides of horizontally oriented traps had the highest capture rates. Direction of traps did not significantly affect capture rate. The infestation rate of leaves was highest (14.1%) the first week of August and generally higher lower on the plant (79.4-100%). No mines were found in the upper region (top third) of the plants. No adults emerged from reared mines. These results are useful in development of sampling protocols to aid growers in making decisions and could be used as an additional component in Integrated Pest Management against L. trifolii in cotton fields

Biological Control of Alfalfa Blotch Leafminer (Diptera: Agromyzidae) in Ontario: Status and Ecology of Parasitoids (Hymenoptera: Braconidae, Eulophidae) 20 Years After Introduction

Two European parasitoid species were released in Ontario during the late 1970\u27s to control the alfalfa blotch leafminer, Agromyza frontella (Rondani) (Diptera: Agromyzidae). One of these, Dacnusa dryas (Nixon) (Hymenoptera: Braconidae), rapidly became established and the other, Chrysocharis liriomyzae (= C. punctifacies) (Delucchi) (Hymenoptera: Eulophidae) was never recovered in Ontario. In 1999, we found both D. dryas and C. liriomyzae parasitizing first-generation A. frontella in Ontario in 1999. The combined parasitism rate for both species as revealed by larval dissections was 97.5% by the end of the first A. frontella generation. Of the adult parasitoids reared, 86% were D. dryas and 14% were C. liriomyzae. Most parasitized larvae contained a single unencapsulated (i.e., healthy) larva, along with one or more encapsulated eggs. No larvae were encapsulated, but the overall egg encapsulation rate was 47%. By the end of the first A. frontella generation, 86% of parasitized hosts contained at least one unencapsulated parasitoid and could therefore produce an adult parasitoid, and 12% of parasitized hosts escaped parasitism by containing only encapsulated parasitoids. The sex ratio of D. dryas was even at emergence, but strongly female-biased in sweep samples from the field. Egg loads of D. dryas females were all greater than zero and as high in the field as our highest laboratory estimates, suggesting that egg availability does not limit fitness under the conditions that we observed in the field

The Distribution and Prevalence of the Alfalfa Blotch Leafminer (Diptera: Agromyzidae) in Illinois

Surveys were made in 2001 and 2002 to determine the distribution and prevalence of the alfalfa blotch leafminer, Agromyza frontella (Diptera: Agromyzidae), and its primary parasitoids, Dacnusa dryas and Chrysocharis liriomyzae (Hymenoptera: Braconidae and Eulophidae, respectively), in Illinois. We collected 239 samples from alfalfa fields in the alfalfa-producing regions of Illinois. Samples from each site consisted of 20 cut stems and 10 sets of 10 sweeps in 2001, and 40 stems and 10 sets of 20 sweeps in 2002. Each trifoliate was examined for mining and pinholing injury, and the number of adult A. frontella, D. dryas, and C. liriomyzae per 10 sweeps was calculated for each site. We found that 16.3% of the sites were infested with A. frontella, and all infested fields were north of 39.95 N latitude. Although up to 95% of stems were injured at some sites, mean injury per stem never exceeded 12% of trifoliates. Maximum adult abundance was 8.1 adults per 10 sweeps. We did not detect D. dryas or C. liriomyzae in any of the sweep samples. Because of consistently low populations and the relatively slow rate of A. frontella’s spread in Illinois, we conclude that A. frontella is not a serious threat to alfalfa production in this state at this time

Insecticide and Growth Regulator Effects on the Leafminer, \u3ci\u3eLiriomyza Trifolii\u3c/i\u3e (Diptera: Agromyzidae), in Celery and Observations on Parasitism

The effects of different insecticides were compared on survival and development of the leafminer, L. trifolii, in celery in Michigan and parasitism was assessed in this non- resident population. Avermectin, thiocyclam, and cyromazine effectively controlled L. trifolii larvae or prevented successful emergence as adults. Moderate to high levels of resistance to permethrin and chlorpyrifos were present. Avermectin caused high mortality of all larval stages and no adults successfully emerged. Thiocyclam caused high mortality to all larval stages, but did not affect adult emergence from the surviving larvae. Cyromazine acted most strongly against early stage larvae before visible mines were present, caused little direct mortality of larger larvae, but prevented successful adult emergence. No parasitoids emerged from 2029 larvae collected and reared, in contrast to studies in sites where L. trifolii is a year-round resident

Population Assessment During the Adult Stage of the Alfalfa Blotch Leafminer, \u3ci\u3eAgromyza Frontella\u3c/i\u3e (Diptera: Agromyzidae)

This paper presents a sampling procedure for estimating adult populations of the alfalfa blotch leafminer, Agromyza frontella (Rondani). The method is based on counts of the flies as they emerge from the soil following adult metamorphosis, taken in a series offurmel traps. Analysis of sampling variability showed that 80 traps per field will give adequate precision for life table studies in alfalfa. The pattern of counts was overdispersed but conformed to the negative binomial distribution