Observations of the Gallery Habits of \u3ci\u3eTrypodendron Retusum\u3c/i\u3e (Coleoptera: Scolytidae) Infesting Aspen in Central Michigan

A monogamous pair of adult Trypodendron retusum construct a gallery system consisting of an entrance tunnel and from two to five lateral tunnels into the sapwood of aspen. Inoculation of the mutualistic fungus Ambrosiella ferruginea by the female beetle, was followed by oviposition in shallow egg cradles. Two instars were observed as the larvae enlarged their cradles. The number of cradles per gallery system was correlated to the length of the gallery system. Progeny adults with a sex ratio of approximately 1:1 emerged from late June to early August to overwinter in the litter

Observations of Xyleborus affinis Eichhoff (Coleoptera:Curculionidae:Scolytinae) in Central Michigan

Xyleborus affinis Eichhoff colonized wind thrown timber in the moist floodplain habitats of Central Michigan. Single adult females constructed a complex gallery system consisting of phloem–sapwood interface tunnels and sapwood tunnels. An average of 24 progeny adults and a sex ratio of 14 females to 1 male were found in mature galleries after the first of September

Gallery Characteristics and Life History of the Ambrosia Beetle Trypodendron betulae (Coleoptera: Curculionidae: Scolytinae) in Birch

Trypodendron betulae Swaine distributed attack entrance holes uniformly over the surface of standing stressed sub-canopy birch trees. Male and female pairs constructed galleries consisting of an entrance tunnel about 20 mm in length and then primary and secondary lateral tunnels averaging between 16 and 23 mm in length into the sapwood. Egg niches were constructed in the lateral tunnels after the symbiotic fungus was established in the galleries. Larvae enlarged the niches into cradles. Pupae and eventually teneral adults developed in the cradles. The sex ratio of resulting progeny adults was approximately one to one, and they emerged from galleries in September to overwinter in the litter

Seasonal Patterns of Flight and Attack of Maple Saplings by the Ambrosia Beetle \u3ci\u3eCorthylus Punctatissimus\u3c/i\u3e (Coleoptera: Scolytidae) in Central Michigan

Window traps with ethanol were used to observe seasonal flight patterns of Corthylus punctatissimus in central Michigan. Flights peaked in early July with a second peak seven weeks later in late August. Similarly, wilting of attacked maple (Acer) saplings began to appear a week after initial Corthylus flights, and showed twopeaks, one in mid-July and again with another peak, seven weeks later, in early September. The second peak of activity is presumably from reemerged adults, and not a second generation

Distribution and Host Plants of \u3ci\u3eCorthylus Punctatissimus\u3c/i\u3e (Coleoptera: Scolytidae) in the Lower Peninsula of Michigan

(excerpt) The pitted ambrosia beetle. Corthylus punctatissimus Zimmerman, infests woody saplings and shrubs 14 mm in diameter or less. The beetle bores an entrance hole into the main stem at soil level and constructs a main gallery tunnel which generally spirals downward in the stem. Egg-niche construction is followed by inoculation of symbiotic fungi and oviposition. The main stem of the host tree wilts as a result of the girdling activity of the beetle. Finnegan (1967) described the life history of C. punctatissimus infesting Acer saccharum Marshall in Ontario and Quebec

Observations of the Habits of \u3ci\u3eCorthylus Punctatissimus\u3c/i\u3e (Coleoptera: Scolytidae) Infesting Maple Saplings in Central Michigan

Corthylus punctatissimus, the pitted ambrosia beetle, infested and killed maple saplings that were 3-12 years of age with a basal diameter of 4-14 mm. The habits of the parental pair of adults are described. The beetles construct a spiral gallery system with about five egg niches per host. Half the brood reaches adult stage during the summer with a sex ratio of 1:1. No relationship was found between the number of niches, length of gallery system, or diameter of stem

Essays on the Economic Well-Being of Women

This dissertation consists of three chapters: 1. The Effect of College Distance on Economic Opportunity for Low-Income Youth This chapter studies the impact of one obstacle to college completion among low-income youth: geographic distance to the nearest four-year public college. The chapter\u27s main results show that cutting the distance to a public four-year college from its mean value of 18 miles to half of that, 9 miles, is associated with a 4 percentage point increase in the college graduation rate of low-income women. Reducing the distance to public community college also increases the probability of completing college for low-income women. These effects are robust to controlling for socioeconomic background, environment, and standardized test scores. Low-income men, who have much lower college graduation rates than their female counterparts, do not appear to be affected by distance to a public college. Policymakers should consider this finding when deciding whether to establish new campuses of public college systems or to consolidate two existing campuses. 2. A Cross-National Study of the Gender Gap in the Economic Consequences of Divorce: Decomposing the Effects of Custody, Wage Rates, and Tax and Transfer Programs This chapter estimates the economic consequences of divorce by gender in six different developed economies. Across all countries studied, women fare worse than men, due to lower average labor income and a higher likelihood of being responsible for children post-divorce. For each country we test the impact on the economic consequences of divorce of: (a) equalizing average wage rates between men and women of similar levels of education, (b) re-assigning custody of all children to men, and (c) imposing the tax and transfer programs of other countries on the United States. We find that divorcing women in the United States experience worse levels of economic well-being on average than men, and that the discrepancy is larger in the United States than in the other countries we study. The gap between the United States and other countries is mostly due to differences in tax and transfer policies and fertility rates prior to divorce. 3. Maternity Leave for Teen Mothers: The Impact of Short-Run Interruptions in Schooling This chapter examines a previously unexplored causal mechanism determining the impact of teen motherhood on educational outcomes. Specifically, I identify the impact of the short-term disruption to school attendance induced by child birth and recovery, as opposed to the ongoing burden of raising a young child. Using administrative data on teen mothers in the New York City public school system, I exploit exogenous variation in the timing of births relative to the academic year to identify the impact of a marginal absence on standardized test scores and the likelihood of successfully graduating

An in-depth investigation of interval temporal logic model checking with regular expressions

In the last years, the model checking (MC) problem for interval temporal logic (ITL) has received an increasing attention as a viable alternative to the traditional (point-based) temporal logic MC, which can be recovered as a special case. Most results have been obtained by imposing suitable restrictions on interval labeling. In this paper, we overcome such limitations by using regular expressions to define the behavior of proposition letters over intervals in terms of the component states. We first prove that MC for Halpern and Shoham’s ITL (HS), extended with regular expressions, is decidable. Then, we show that formulas of a large class of HS fragments, namely, all fragments featuring (a subset of) HS modalities for Allen’s relations meets, met-by, starts, and started-by, can be model checked in polynomial working space (MC for all these fragments turns out to be PSPACE-complete)

Eliminating Ditransitives

Abstract. We discuss how higher arity verbs such as give or promise can be treated in an algebraic framework that admits only unary and binary relations and does not rely on event variables

Inconsistent boundaries

Research on this paper was supported by a grant from the Marsden Fund, Royal Society of New Zealand.Mereotopology is a theory of connected parts. The existence of boundaries, as parts of everyday objects, is basic to any such theory; but in classical mereotopology, there is a problem: if boundaries exist, then either distinct entities cannot be in contact, or else space is not topologically connected (Varzi in Noûs 31:26–58, 1997). In this paper we urge that this problem can be met with a paraconsistent mereotopology, and sketch the details of one such approach. The resulting theory focuses attention on the role of empty parts, in delivering a balanced and bounded metaphysics of naive space.PostprintPeer reviewe