Interrelations of the Squash Bug, Anasa tristis, and Six Varieties of Squash (Cucurbita Spp.)1

In the course of an investigation of insects affecting cucurbits, begun in a preliminary way in the season of 1897, as a part of the official work of the Division of Entomology of the Department of Agriculture, it was found that we have in addition to the common squash bug, Anasa tristis, DeG., a second species sufficiently resembling it as to have readily escaped the notice of the average observer, but at the same time quite distinct in all its stages. This species is Anasa armigera, Say, and it was first observed on cucurbits by the writer July 12, near colonial Beach, Va., where it occured on cucumbers. Afterward it was taken by the writer and Mr. F. C. Pratt, of the Division of Entomology, who has assisted in field investigations and collections on different cucurbits, at Ballston, Va., Poolesville and Seat pleasant, Md., and on the Conduit Road and at Tenleytown, D. C. At the last mentioned place it occured in great abudance on a late crop of cucumbers and watermelons. As late as the 29th of September, all stages of the insect were found, including the egg. The present year the species was found to be nearly as abundant in some locaties as the common squash bug. Such was the case at Marshall Hall, Md., and in one locality in the District of columbia. It was also observed on squash at College Station and Kensington, Md., and on cucumber at Cabin John, Md.

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The importance of environmentally-acquired bacterial symbionts for the squash bug (Anasa tristis), a significant agricultural pest

10.1101/2021.07.14.452367 ◽

2021 ◽

Author(s):

Tarik S. Acevedo ◽

Gregory P. Fricker ◽

Justine R Garcia ◽

Tiffany Alcaide ◽

Aileen Berasategui ◽

...

Keyword(s):

Horizontal Transmission ◽

Development Stage ◽

Bacterial Symbionts ◽

Complete Understanding ◽

Anasa Tristis ◽

Squash Bug ◽

The Family ◽

Insect Symbionts ◽

Midgut Crypts ◽

Bacterial Plant Pathogen

Most insects maintain associations with microbes that shape their ecology and evolution. Such symbioses have important applied implications when the associated insects are pests or vectors of disease. The squash bug, Anasa tristis (Coreoidea: Coreidae), is a significant pest of human agriculture in its own right and also causes damage to crops due to its capacity to transmit a bacterial plant pathogen. Here, we demonstrate that complete understanding of these insects requires consideration of their association with bacterial symbionts in the family Burkholderiaceae. Isolation and sequencing of bacteria housed in midgut crypts in these insects indicates that these bacteria are consistent and dominant members of the crypt-associated bacterial communities. These symbionts are closely related to Caballeronia spp. associated other true bugs in the superfamiles Lygaeoidea and Coreoidea. Fitness assays with representative Burkholderiaceae strains indicate that the association can significantly increase survival and decrease development time, though strains do vary in the benefits that they confer to their hosts, with Caballeronia spp. providing the greatest benefit. Experiments designed to assess transmission mode indicate that unlike many other beneficial insect symbionts, the bacteria are not acquired from parents before or after hatching but are instead acquired from the environment after molting to a later development stage. The bacteria do, however, have the capacity to escape adults to be transmitted to later generations, leaving the possibility for a combination of indirect vertical and horizontal transmission.

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The Importance of Environmentally Acquired Bacterial Symbionts for the Squash Bug (Anasa tristis), a Significant Agricultural Pest

Frontiers in Microbiology ◽

10.3389/fmicb.2021.719112 ◽

2021 ◽

Vol 12 ◽

Author(s):

Tarik S. Acevedo ◽

Gregory P. Fricker ◽

Justine R. Garcia ◽

Tiffanie Alcaide ◽

Aileen Berasategui ◽

...

Keyword(s):

Bacterial Communities ◽

Horizontal Transmission ◽

Bacterial Symbionts ◽

Complete Understanding ◽

Anasa Tristis ◽

Squash Bug ◽

The Family ◽

Insect Symbionts ◽

Midgut Crypts ◽

Bacterial Plant Pathogen

Most insects maintain associations with microbes that shape their ecology and evolution. Such symbioses have important applied implications when the associated insects are pests or vectors of disease. The squash bug, Anasa tristis (Coreoidea: Coreidae), is a significant pest of human agriculture in its own right and also causes damage to crops due to its capacity to transmit a bacterial plant pathogen. Here, we demonstrate that complete understanding of these insects requires consideration of their association with bacterial symbionts in the family Burkholderiaceae. Isolation and sequencing of bacteria housed in the insects’ midgut crypts indicates that these bacteria are consistent and dominant members of the crypt-associated bacterial communities. These symbionts are closely related to Caballeronia spp. associated with other true bugs in the superfamilies Lygaeoidea and Coreoidea. Fitness assays with representative Burkholderiaceae strains indicate that the association can significantly increase survival and decrease development time, though strains do vary in the benefits that they confer to their hosts, with Caballeronia spp. providing the greatest benefit. Experiments designed to assess transmission mode indicate that, unlike many other beneficial insect symbionts, the bacteria are not acquired from parents before or after hatching but are instead acquired from the environment after molting to a later developmental stage. The bacteria do, however, have the capacity to escape adults to be transmitted to later generations, leaving the possibility for a combination of indirect vertical and horizontal transmission.

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Rapid adaptation of squash bug, Anasa tristis, populations to a resistant cucurbit cultivar

Entomologia Experimentalis et Applicata ◽

10.1046/j.1570-7458.1998.00382.x ◽

1998 ◽

Vol 89 (1) ◽

pp. 65-70 ◽

Cited By ~ 6

Author(s):

David C. Margolies ◽

James R. Nechols ◽

Elizabeth A. Vogt

Keyword(s):

Rapid Adaptation ◽

Anasa Tristis ◽

Squash Bug

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Ovipositional Behavior of the Egg Parasitoid Gryon pennsylvanicum (Hymenoptera: Scelionidae) on Two Squash Bug Species Anasa tristis (Hemiptera: Coreidae) and Anasa armigera: Effects of Parasitoid Density, Nutrition, and Host Egg Chorion on Parasitism Rates

Environmental Entomology ◽

10.1093/ee/nvaa118 ◽

2020 ◽

Vol 49 (6) ◽

pp. 1307-1315

Author(s):

Mary L Cornelius ◽

Bryan T Vinyard ◽

Joseph D Mowery ◽

Jing S Hu

Keyword(s):

Electron Microscopy ◽

Laboratory Tests ◽

Egg Parasitoid ◽

Egg Masses ◽

Anasa Tristis ◽

Ovipositional Behavior ◽

Squash Bug ◽

Percent Parasitism ◽

Transmission Electron ◽

Parasitism Rates

Abstract This study examined the ovipositional behavior of Gryon pennsylvanicum Ashmead (Hymenoptera: Scelionidae) on egg masses of two squash bug species Anasa tristis DeGeer and Anasa armigera Say (Hemiptera: Coreidae) by evaluating how parasitoid density and access to nutrition influenced percent parasitism on egg masses of different sizes in laboratory tests. When three parasitoids were exposed to A. tristis egg masses with only three to five eggs, 72.7% of parasitoids became trapped in the eggs and failed to emerge successfully. These results suggest that competition between larvae within the egg may have reduced the fitness of the surviving parasitoid. Continual access to honey water did not significantly influence parasitism rates on A. armigera egg masses and only increased parasitism on A. tristis egg masses with 20–25 eggs. Overall, parasitism rates were higher on A. armigera egg masses than on A. tristis egg masses, and parasitoids were more likely to emerge successfully from A. armigera eggs than from A. tristis eggs. Parasitoids spent the same amount of time probing eggs of the two species, but they spent significantly more time drilling into A. tristis eggs than A. armigera eggs. Measurements taken using transmission electron microscopy determined that the average combined width of the epicuticle and exocuticle of the egg chorion was significantly greater for A. tristis eggs than for A. armigera eggs. This difference may account for the lower rates of parasitism and parasitoid emergence and for the increased time spent drilling into A. tristis eggs compared with A. armigera eggs.

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